PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Silva D.C.B., Fagundes N.C.F., Teixeira F.B., Penha N.E.A., Santana L.N.S., Oliveira A.C.M. & Lima R.R. 2013. Anatomical and histological characteristics of teeth in agouti (Dasyprocta prymnolopha Wagler, 1831). Pesquisa Veterinária Brasileira 33(Supl.1):51-57. Laboratório de Biologia Estrutural e Funcional, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa 1, Guamá, Belém, PA 66075-900, Brazil. E-mail: rafalima@ufpa.br The agouti species Dasyprocta prymnolopha (D. prymnolopha) is a medium-sized rodent, diurnal, and characteristic of northeastern Brazil, south of the Amazon. Several studies have been made on these rodents. However, there is a lack of analysis of masticatory system, in particular morphology of the teeth. Thus, this research seeks to describe anatomical and histological aspects of the agouti teeth. For this purpose, we used adult agouti, in which measurements and descriptions of teeth and dental tissues were made. It was observed that the dental arch of D. prymnolopha comprises of twenty teeth, evenly distributed in the upper and lower arch, being inferior teeth larger than their corresponding higher. The incisors are larger, and between the posterior premolars and molars, there is a gradual increase in length in the anterior-posterior arch. In microscopic examination, a prismatic appearance was observed consisting of enamel prisms arranged in different directions, behind the enamel and dentin with standard tubular dentinal tubules with variable diameter and far between, also showing a sinuous path from the inner portion to the junction with more superficial enamel. Morphological analysis of dental tissues showed that an enamel with structural organization adapted to the act of chewing and high impact dentin compatible with standard tubular function resilience and mechanical damping of masticatory forces, as found in larger animals, confirming the understanding of eating habits that define much of its ecological functions within the ecosystem they inhabit.

• Teeth agouti Dasyprocta prymnolopha dentes cutia

Abstract in Portuguese:

RESUMO.- Silva D.C.B., Fagundes N.C.F., Teixeira F.B., Penha N.E.A., Santana L.N.S., Oliveira A.C.M. & Lima R.R. 2013. Anatomical and histological characteristics of teeth in agouti (Dasyprocta prymnolopha Wagler, 1831). [Características anatômicas e histológicas dos dentes na cutia (Dasyprocta prymnolopha Wagler, 1831).] Pesquisa Veterinária Brasileira 33(Supl.1):51-57. Laboratório de Biologia Estrutural e Funcional, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa 1, Guamá, Belém, PA 66075-900, Brazil. E-mail: rafalima@ufpa.br A cutia espécie Dasyprocta prymnolopha (D. prymnolopha) é um roedor de tamanho médio, diurno e característico do Nordeste do Brasil, sul da Amazônia. Vários estudos têm sido feitos sobre estes roedores. No entanto, há uma carência de estudos do sistema estomatognático, em particular, a morfologia dos dentes. Assim, esta pesquisa procura descrever aspectos anatômicos e histológicos dos dentes cutia. Para isto, nós utilizamos cutias adultas, em que as mensurações e as descrições dos dentes e dos tecidos dentais foram feitas. Observou-se que a arcada dentária de D. prymnolopha é composta por vinte dentes, distribuídas uniformemente no arco superior e inferior, sendo os dentes inferiores, maiores do que os seus correspondentes superiores. Os incisivos são maiores, e entre os pré-molares e molares posteriores, existe um aumento gradual no comprimento do arco anterior-posterior. No exame microscópico, uma forma prismática foi observada o que consiste de prismas de esmalte dispostos em diferentes direções, atrás do esmalte e dentina com túbulos dentinários com padrão tubular de diâmetro variável e distantes entre si, mostrando também um caminho sinuoso a partir da parte interna da junção com o esmalte mais superficial. A análise morfológica dos tecidos dentários mostrou um esmalte com a organização estrutural adaptada para o ato de mastigar e dentina de alto impacto compatível com a função do padrão tubular de resiliência e amortecimento mecânico de forças mastigatórias, como encontrado em animais maiores, confirmando o entendimento de hábitos alimentares que definem muito das suas funções ecológicas dentro do ecossistema em que vivem.

Abstract in English:

ABSTRACT.- Oliveira F.S., Martins L.L., Canola J.C., Oliveira P.T., Pécora J.D. & Pauloni A.P. 2012. Macroscopic description of teeth of Azara´s agouti (Dasyprocta azarae). Pesquisa Veterinária Brasileira 32(1):93-95. Departamento de Medicina Veterinária, Universidade Estadual de Maringá, Campus Umuarama, Cx. Postal 65, Umuarama, PR 87501-970, Brazil. E-mail: singaretti@ig.com.br The teeth of Azara´s agouti (Dasyprocta azarae) were described macroscopically in order to provide biological data on one of the largest wild rodents of the Americas. Radiography was taken on six heads and the teeth were described. Enamel surrounds the coronal dentin, projects to the roots and is present as parallel inner laminae in buccolingual direction. The dentin is located among the enamel laminae and surrounds the pulp horns. The cementum is located internally to the enamel laminae. On the lingual surface, the cementum and dentin are the outer elements.

• Teeth Dasyprocta azarae agouti dentes cutia

Abstract in Portuguese:

RESUMO.- Oliveira F.S., Martins L.L., Canola J.C., Oliveira P.T., Pécora J.D. & Pauloni A.P. 2012. Macroscopic description of teeth of Azara´s agouti (Dasyprocta azarae). Pesquisa Veterinária Brasileira 32(1):93-95. Departamento de Medicina Veterinária, Universidade Estadual de Maringá, Campus Umuarama, Cx. Postal 65, Umuarama, PR 87501-970, Brazil. E-mail: singaretti@ig.com.br Os dentes de cutias (Dasyprocta azarae) foram descritos macroscopicamente para fornecer informações sobre um dos maiores roedores das Américas. Radiografias foram realizadas em seis cabeças, e os dentes foram descritos. O esmalte envolve a dentina coronal e se projeta até a raiz e é presente como lâminas dispostas paralelamente em direção vestíbulolingual. A dentina é localizada entre as lâminas do esmalte e envolve os cornos pulpares. O cemento é localizado internamente às lâminas de esmalte. Na superfície lingual, o cemento e a dentina são os elementos mais externos.

Abstract in English:

ABSTRACT.- Pieri N.C.G., Mançanares C.A.F., Bertassoli B., Lima J.M.N.,Thomaz J. M. & Carvalho A.F. 2011. [Teeth morphofunctional classification of coati, Nasua nasua.] Classificação morfofuncional dos dentes de quati, Nasua nasua. Pesquisa Veterinária Brasileira 31(5):447-451. Departamento de Ciências Morfológicas, Centro Universitário da Fundação de Ensino Octávio Bastos, Av. Doutor Octávio Bastos s/n, Jardim Nova São João, São João da Boa Vista, SP 13874-148, Brazil. E-mail: labvet01@unifeob.edu.br Nasua nasua, also known as coati, is an omnivorous mammal with wide distribution in South America and found all over Brazil. The evolution adapted the teeth of the multiple mammals for most different diets. Through these variations it is possible to classify the vertebrates´ teeth of vertebrates in classes, genera and families. The objective of this paper is to describe and classify morphologically the teeth of Nasua nasua, comparing them with the teeth of Canis familiaris described in the literature. Five adult male and female Nasua nasua were studied. Photographs of the oral cavity of two macerated skulls were taken for documentation of teeth position. From other three animals, teeth were processed for decalcification and embedded in paraffin for histology. It was possible to reveal macroscopically male and female differences in N. nasua, due to a sexual dimorphism. Female have smaller round canine teeth, and male canine teeth are larger than the female ones. The animals presented the dental formula 2x (I3/3, C1/1, P4/4, M2/2) (I=incisive, C=canine, P=premolar, M=molar), with a total of 40 teeth. Microscopically, the teeth were classified as brachyodont with enamel in the most external region, covering the dentine. This type of teeth does not erupt constantly as the hypsodonts, because the enamel stays intact until the time of eruption. Teeth were also classified as anelodont, with a limited period of growth characteristics.

• Dental formula Nasua nasua teeth Procyonidae fórmula dentária dentes

Abstract in Portuguese:

RESUMO.- Pieri N.C.G., Mançanares C.A.F., Bertassoli B., Lima J.M.N.,Thomaz J. M. & Carvalho A.F. 2011. [Teeth morphofunctional classification of coati, Nasua nasua.] Classificação morfofuncional dos dentes de quati, Nasua nasua. Pesquisa Veterinária Brasileira 31(5):447-451. Departamento de Ciências Morfológicas, Centro Universitário da Fundação de Ensino Octávio Bastos, Av. Doutor Octávio Bastos s/n, Jardim Nova São João, São João da Boa Vista, SP 13874-148, Brazil. E-mail: labvet01@unifeob.edu.br O quati (Nasua nasua), é um mamífero onívoro, amplamente distribuído pela América do sul e encontrado em todo Brasil. A evolução provocou nos dentes dos mamíferos múltiplas variações, adequando às mais diversas dietas. Por essas variações nos dentes é possível classificar os vertebrados em ordem, gênero e família. Portanto este trabalho teve como objetivo descrever e classificar morfologicamente os dentes de machos e fêmeas de N. nausa, a fim de classificá-los e compará-los entre si e com a morfologia dos dentes de Canis familiaris descrita na literatura. Neste estudo foram utilizados cinco animais Nasua nasua, adultos, de ambos os sexos, cedidas pelo Criatório Cientifico Cecrimpas (Unifeob). Dois deles macerados tiveram a cavidade oral exposta para a realização da documentação fotográfica da posição dos dentes, outros três, os dentes foram submetidos à descalcificação e processamento e embebição em parafina para observação histológica. Na cavidade oral de N. nasua, devido ao dimorfismo sexual, foi possível comparar a dentição do macho e da fêmea macroscopicamente. A fêmea apresentou dentes menores, caninos arredondados e o macho, caninos maiores. Os animais apresentaram a fórmula dentária 2x(I3/3, C1/1, P4/4, M2/2) (I=incisivos, C=caninos, P=pré-molares e M=molares) = 40. Microscopicamente todos os dentes foram classificados como braquidontes, pois o esmalte é depositado sobre a dentina. Este tipo de dente não tem erupção constante como o hipsodonte, pois seu esmalte permanece intacto até a época de erupção. Seus dentes também foram classificados como anelodontes, por ter um período limitado de características de crescimento.

Abstract in English:

ABSTRACT.- Abdalla S.L., Silva M.F.A., Pereira A.R.C., Azevedo F.D., Fernandes J.I., Minono G.P. & Botelho R.P. 2009. [Computer quantification for the evaluation of dental plaque and dental calculus index in the digital image of vestibular surface of the teeth of dogs.] Quantificação computadorizada dos índices de placa e cálculo dentais da imagem digital da superfície vestibular dos dentes de cães. Pesquisa Veterinária Brasileira 29(8):666-672. Departamento de Medicina e Cirurgia Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: abdallasamira@hotmail.com Periodontal disease is caused by dental plaque accumulation on teeth and adjacent structures. Indices have been formulated for its measurement considering the amount and intensity of dental plaque (DP) and dental calculus (C) on the surface of teeth through subjective visual evaluation. This study aims at assessing the computerized analysis method for measurement of DP and C areas on the teeth of dogs by comparing it with the visual evaluation in the oral cavity. Ten beagle dogs with similar characteristics and kept under the same management and diet were used. Evaluations of oral cavity occurred before surgical prophylaxis (performed under general inhalation anesthesia) and after seven days for DP and 28 days for C. The computerized C area evaluation showed to be statistically better than the visual evaluation before and after prophylaxis. It was concluded that the computerized evaluation is beneficial when compared to visual evaluation, providing greater precision in the area measurement.

• Dental plaque dental calculus

Abstract in Portuguese:

RESUMO.- Abdalla S.L., Silva M.F.A., Pereira A.R.C., Azevedo F.D., Fernandes J.I., Minono G.P. & Botelho R.P. 2009. [Computer quantification for the evaluation of dental plaque and dental calculus index in the digital image of vestibular surface of the teeth of dogs.] Quantificação computadorizada dos índices de placa e cálculo dentais da imagem digital da superfície vestibular dos dentes de cães. Pesquisa Veterinária Brasileira 29(8):666-672. Departamento de Medicina e Cirurgia Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: abdallasamira@hotmail.com A doença periodontal é causada pelo acúmulo de placa bacteriana sobre os dentes e estruturas adjacentes. Para sua mensuração têm sido formulados índices que consideram a quantidade e intensidade de placa bacteriana (PB) e de cálculo dental (CD) existentes na superfície dentária por meio de avaliação visual subjetiva. O presente estudo tem como objetivo avaliar o método de análise computadorizada para medição de área de PB e CD nos dentes de cães através da comparação com a avaliação visual. Foram utilizados 10 cães Beagles, três machos e sete fêmeas, com similares características e mantidos sob o mesmo manejo e dieta alimentar. As avaliações das superfícies vestibulares dos dentes ocorreram antes da profilaxia dentária, que foi realizada sob anestesia geral inalatória, e após sete dias para PB e após 28 dias para CD. A avaliação computadorizada da área de CD demonstrou ser estatisticamente melhor em relação à avaliação visual antes e após a profilaxia; entretanto, não demonstrou diferença significante na avaliação da PB. Concluiu-se que a avaliação computadorizada é vantajosa em relação à visual por conferir maior precisão na obtenção da proporção entre área total do dente e área acometida, mostrando-se estatistticamente superior na quantificação do CD após 28 dias.

Abstract in English:

ABSTRACT.- Koller F.L., Borowski S.M., Asanome W., Hein G., Lagemann F.L., Driemeier D. & Barcellos D.E.S.N. 2008. [Dental periapical abscesses in piglets affected by postweaning multisystemic wasting syndrome PMWS.] Abscessos dentários periapi-cais em leitões com síndrome multissistêmica do definhamento. Pesquisa Veterinária Brasi-leira 28(6):271-274. Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Porto Alegre RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br Swine producers have historically resected needle teeth of newborn pigs to prevent potential injuries to the sow mammary gland and faces of littermates. However, the possible impact of this practice on pig performance has been questioned. As part of a study, 280 PMWS affected piglets, with 40-70 days of age, were examined for the presence of dental lesions immediately after euthanasia. Most pigs were confirmed as PMWS by the detection of typical microscopic lesions and immunohistochemical pattern. At least one periapical abscess was observed in 58 piglets (20.7%), of which 12 had multiple abscesses. There were 22 (31.4%), 16 (22.9%), 4 (5.7%), 23 (32.9%), and 5 (7.1%) abscesses in 3rd upper incisives, 3rd lower incisives, upper canines, lower canines, and other teeth, respectively. The higher prevalence of dental abscesses observed in 3rd incisives and lower canines is probably associated with the wider area of grinding or clipping to which these teeth were subjected. Among bacteria isolated from samples collected from 65 abscesses, Streptococcus sp. was the most prevalent bacteria and was present in 21.48% and 27.7% of the aerobic and anaerobic isolates, respectively. In the second most frequent group were coryneform microorganisms, which showed higher rate of isolation under anaerobic atmosphere than in aerobic culture. There was preponderance of Gram-positive isolates. It could not be determined whether these bacterial co-infections predisposed pigs to development of PMWS-type lesions or if were subsequent to the PCV2 infection.

• Periapical abscess causal bacteria co-infection PMWS piglet teeth resection teeth clipping

Abstract in Portuguese:

ABSTRACT.- Koller F.L., Borowski S.M., Asanome W., Hein G., Lagemann F.L., Driemeier D. & Barcellos D.E.S.N. 2008. [Dental periapical abscesses in piglets affected by postweaning multisystemic wasting syndrome PMWS.] Abscessos dentários periapi-cais em leitões com síndrome multissistêmica do definhamento. Pesquisa Veterinária Brasi-leira 28(6):271-274. Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Porto Alegre RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br Swine producers have historically resected needle teeth of newborn pigs to prevent potential injuries to the sow mammary gland and faces of littermates. However, the possible impact of this practice on pig performance has been questioned. As part of a study, 280 PMWS affected piglets, with 40-70 days of age, were examined for the presence of dental lesions immediately after euthanasia. Most pigs were confirmed as PMWS by the detection of typical microscopic lesions and immunohistochemical pattern. At least one periapical abscess was observed in 58 piglets (20.7%), of which 12 had multiple abscesses. There were 22 (31.4%), 16 (22.9%), 4 (5.7%), 23 (32.9%), and 5 (7.1%) abscesses in 3rd upper incisives, 3rd lower incisives, upper canines, lower canines, and other teeth, respectively. The higher prevalence of dental abscesses observed in 3rd incisives and lower canines is probably associated with the wider area of grinding or clipping to which these teeth were subjected. Among bacteria isolated from samples collected from 65 abscesses, Streptococcus sp. was the most prevalent bacteria and was present in 21.48% and 27.7% of the aerobic and anaerobic isolates, respectively. In the second most frequent group were coryneform microorganisms, which showed higher rate of isolation under anaerobic atmosphere than in aerobic culture. There was preponderance of Gram-positive isolates. It could not be determined whether these bacterial co-infections predisposed pigs to development of PMWS-type lesions or if were subsequent to the PCV2 infection.

Abstract in English:

ABSTRACT.- Domingues-F. L.M., Gioso M.A. & Padilha Filho J.G. 2007. Histopathological and histomicrobiological study of root canal therapy medication, comparison of calcium hydroxide versus gutta-percha with zinc oxide/eugenol in the teeth of dogs. Pesquisa Veterinária Brasileira 27(2):71-74. Departamento de Cirurgia da Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando de Marques de Paiva 87, Bloco 8-superior, Cidade Universitária, São Paulo, SP 05508-000, Brazil. E-mail: lesliedf@usp.br The presence of microorganisms in dental structures with experimentally induced necrosis was evaluated. The materials were tested to evaluate their antimicrobial activity and tissue repair efficacy. Four dogs were used in this experiment, with a total of 64 roots of premolar teeth, divided into three groups. The root canals of Group I were filled with gutta-percha and zinc oxide/eugenol cement; Group II were filled with calcium hydroxide, and Group III were not filled. All animals were clinically and radiographically examined 15 days after surgery and then again every subsequent 15 days until 120 days, when the teeth were extracted en bloc. Histopathological analysis showed inflammatory infiltration, cement and bone resorption and necrotic tissue in the apical delta in different proportions. Histomicrobiological analysis showed the presence of microorganisms inside the teeth structures, with different concentrations according to the treatment used. There was statistical significance between the groups (p>0.05). Gutta-percha with zinc oxide/eugenol demonstrated good antimicrobial activity; calcium hydroxide was not efficient. The conclusion of this study is that gutta-percha with zinc oxide/eugenol is the better protocol for filling root canals in dogs.

• Apical delta endodontic gutta-percha calcium hidroxide microorganisms dogs

Abstract in Portuguese:

ABSTRACT.- Domingues-F. L.M., Gioso M.A. & Padilha Filho J.G. 2007. Histopathological and histomicrobiological study of root canal therapy medication, comparison of calcium hydroxide versus gutta-percha with zinc oxide/eugenol in the teeth of dogs. Pesquisa Veterinária Brasileira 27(2):71-74. Departamento de Cirurgia da Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando de Marques de Paiva 87, Bloco 8-superior, Cidade Universitária, São Paulo, SP 05508-000, Brazil. E-mail: lesliedf@usp.br The presence of microorganisms in dental structures with experimentally induced necrosis was evaluated. The materials were tested to evaluate their antimicrobial activity and tissue repair efficacy. Four dogs were used in this experiment, with a total of 64 roots of premolar teeth, divided into three groups. The root canals of Group I were filled with gutta-percha and zinc oxide/eugenol cement; Group II were filled with calcium hydroxide, and Group III were not filled. All animals were clinically and radiographically examined 15 days after surgery and then again every subsequent 15 days until 120 days, when the teeth were extracted en bloc. Histopathological analysis showed inflammatory infiltration, cement and bone resorption and necrotic tissue in the apical delta in different proportions. Histomicrobiological analysis showed the presence of microorganisms inside the teeth structures, with different concentrations according to the treatment used. There was statistical significance between the groups (p>0.05). Gutta-percha with zinc oxide/eugenol demonstrated good antimicrobial activity; calcium hydroxide was not efficient. The conclusion of this study is that gutta-percha with zinc oxide/eugenol is the better protocol for filling root canals in dogs.

Abstract in English:

ABSTRACT.- Domingues-F.L.M., Ferreira J., Lopes F.M., Tymoszczenko A. & Gioso M.A. 2007. The effect of timing temporary cements to treat induced pulp necrosis in the teeth of dogs. Revista Pesquisa Veterinária Brasileira 27(2):85-88. Departamento de Cirurgia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando de Marques de Paiva 87, Bloco 8-superior, Cidade Universitária, São Paulo, SP 05508-000, Brazil. E-mail: lesliedf@usp.br During endodontic therapy (pulpectomy, root canal debridement and root canal filling) microbiological management is a major concern. Bacteria present in dentine tubules, apical foramina and apical delta are causally related to failure of the procedure. Studies have shown that during single session endodontic treatment bacteria remain within dental structures. The aim of the present study was to evaluate endodontic treatment performed as two sessions, using temporary endodontic dressing materials for different periods in four groups of experimental dogs. A total of 80 roots of second and third upper premolar teeth and second, third and fourth lower premolar teeth were divided into four groups. The pulp chamber was opened with burrs and the pulp exposed for 60 days to induce pulpal inflammation and necrosis. Groups II, III and IV were treated with calcium hydroxide plus camphorated paramono-chlorophenol (PMCC) for 7, 15 and 30 days, respectively. In all groups, the root canals were filled with zinc oxide-eugenol and gutta-percha cones. Clinical and radiographical measurements were performed every 2 weeks. After 60 days a small block section containing the teeth, surrounding periapical tissues and the periodontium was removed for histological and microbiological study. Histological analysis revealed intense inflammatory response in all groups. Microbiological analysis showed microbial reduction inversely proportional to the period of time that the intracanal temporary medicament was left in place.

• Apical delta endodontic gutta-percha camphorated paramonochlorophenol microorganisms dogs

Abstract in Portuguese:

ABSTRACT.- Domingues-F.L.M., Ferreira J., Lopes F.M., Tymoszczenko A. & Gioso M.A. 2007. The effect of timing temporary cements to treat induced pulp necrosis in the teeth of dogs. Revista Pesquisa Veterinária Brasileira 27(2):85-88. Departamento de Cirurgia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando de Marques de Paiva 87, Bloco 8-superior, Cidade Universitária, São Paulo, SP 05508-000, Brazil. E-mail: lesliedf@usp.br During endodontic therapy (pulpectomy, root canal debridement and root canal filling) microbiological management is a major concern. Bacteria present in dentine tubules, apical foramina and apical delta are causally related to failure of the procedure. Studies have shown that during single session endodontic treatment bacteria remain within dental structures. The aim of the present study was to evaluate endodontic treatment performed as two sessions, using temporary endodontic dressing materials for different periods in four groups of experimental dogs. A total of 80 roots of second and third upper premolar teeth and second, third and fourth lower premolar teeth were divided into four groups. The pulp chamber was opened with burrs and the pulp exposed for 60 days to induce pulpal inflammation and necrosis. Groups II, III and IV were treated with calcium hydroxide plus camphorated paramono-chlorophenol (PMCC) for 7, 15 and 30 days, respectively. In all groups, the root canals were filled with zinc oxide-eugenol and gutta-percha cones. Clinical and radiographical measurements were performed every 2 weeks. After 60 days a small block section containing the teeth, surrounding periapical tissues and the periodontium was removed for histological and microbiological study. Histological analysis revealed intense inflammatory response in all groups. Microbiological analysis showed microbial reduction inversely proportional to the period of time that the intracanal temporary medicament was left in place.